What mods for 1999 v6 mustang?

It's missing two cylinders, so what's the point? Honestly, really, and truly don't waste your money.

www.barryboys.co.uk will show you what happens when people start with the wrong base car.

If you could do all that yourself it would be around that price. Labor costs would be high for stuff like the gears and maybe differential. The CAI, you can do easily yourself. Exhaust from a custom shop would be like 200-300 depending on what you want or you can buy a predone exhaust kit and bolt it on yourself and have an exhaust shop weld it together, tune should be around that same price, and shorty headers should be easy enough to do yourself, unless you break a bolt or the stock manifolds are stuck on there, then an exhaust shop can install them for you. You can save a lot of money by doing automotive stuff yourself, a lot of people don't realize that if they learn a little about cars, it can save a lot of money, but some stuff you either can't do, don't have time for or don't have the equipment to do.

A 305 V8 swap. But since your dead set on the V6 an aggressive cam and full exhaust would be really all you could afford that would be worth it, maybe even new injectors and intake... that would be more then enough to put any honda in its place. from there pinch your pennies and start working on the clutch and trans so you dont fry it like all newbies who go all motor do. Seriously any major mods will **** your tranny up something awful

You're going about your project backwards. The 3.8 liter Ford engine (discontinued) was one of the worst engines Ford ever had the pleasure of dropping on its head. Why not invest on another Ford engine that has a few more grapes.